Color diffusion transfer process utilizing azo coupling to actuate diffusion of color providing species

ABSTRACT

In a color diffusion transfer process utilizing azo coupling as a means to actuate solubilization and to accelerate the diffusion transfer process of color providing species, light sensitive layers are provided which contain oil dispersions of 4-equivalent color formers capable of coupling in the alkaline processing solution with the oxidation product of a p-phenylene diamine color developer and thereby form imagewise non-diffusible and insoluble dye species. These color formers are also capable of reacting with incorporated highly diffusible carboxy or sulfo substituted diazonium salts or their precursors to yield alkali soluble and highly diffusible azo dyes which diffuse imagewise to a mordanted receiving layer. In the receiving layer a p-phenylene diamine developer is oxidized for the purpose of converting these azo dyes via oxidative coupling into azo methine or indoaniline dye species thereby providing a true reproduction in color, hue and density of the scene originally recorded in the light sensitive silver halide layers.

United States Patent Viro et al.

[ COLOR DIFFUSION TRANSFER PROCESS UTILIZING AZO COUPLING TO ACTUATEDIFFUSION OF COLOR PROVIDING SPECIES [75] Inventors: Felix Viro,Apalachin; Robert Thomas Shannahan, Endicott; Burton Harvey Waxman,Endwell, all of NY.

[73] Assignee: GAF Corporation, New York, NY.

[22] Filed: Oct. 2, 1972 [21] Appl. No.: 293,940

[52] US. Cl 96/3, 96/29 D, 96/77 [51] Int. Cl. G03c 7/00, G03c l/00,G030 1/40 [58] Field of Search 96/3, 77, 29 D [56] References CitedUNITED STATES PATENTS 3,065,074 11/1962 Rogers 96/3 3,301,772 1/1967Viro 96/3 3,359,104 12/1967 Viro i r 96/3 3,676,124 7/1972 Ohkubo et al.96/3 EXPOSURE AAAAAA AAAAAA AAA AAAAAAA AAAAAA AA,AAAA

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[ Sept. 24, 1974 Primary Examiner-Ronald H. Smith AssistantExaminerRichard L. Schilling Attorney, Agent, or FirmWalter C. Kehm;Samson B. Leavitt [5 7 ABSTRACT In a color diffusion transfer processutilizing azo coupling as a means to actuate solubilization and toaccelerate the diffusion transfer process of color providing species,light sensitive layers are provided which contain oil dispersions of4-equivalent color formers capable of coupling in the alkalineprocessing solution with the oxidation product of a p-phenylene diaminecolor developer and thereby form imagewise non-diffusible and insolubledye species. These color formers are also capable of reacting withincorporated highly diffusible carboxy or sulfo substituted diazoniumsalts or their precursors to yield alkali soluble and highly diffusibleazo dyes which diffuse imagewise to a mordanted receiving layer. In thereceiving layer a pphenylene diamine developer is oxidized for thepurpose of converting these azo dyes via oxidative coupling into azomethine or indoaniline dye species thereby providing a true reproductionin color, hue and density of the scene originally recorded in the lightsensitive silver halide layers.

13 Claims, 10 Drawing Figures VIEW AAAAA A A A A A A A A A AAAAA AAAAAAAAAA AAAA AAAA PATENIEB N 398370852 F/G: j EXPOSURE v fwAAAAAAAAAAAAAAAAA 7. 'AAAAAAAAAAAAAAAA 6 AAAAAAAAAAAAAAAAA 5AAAAAAAAAAAAAAAA AAAAAAAAA A 3 AAAAAAAAAAAAAA A AA AAAAAA A AAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAA A AAAAAAAAAAAAAAAA PAIENYEDSEPNIQII3.837, 852

E W v O OH [I v Flat 30 PATENIEBWZMQH 3.837. 852

swmw 6 F/G. 5 EXPOSURE 2 A A AAAAAAAAAAAAAA 7 AAAAAAAAAAAAAAAAAA 6AAAAAAAAAAAAAAAAAA-A AAAAAAAAAAAAAAAAA'A 5 4 AAAAAAAAAAAA AAAAAA 3AAAAAAAA AAAAAAAA 8, l7 ll l2 VIEW 4 I ()EXPOSURE AAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAA AA AA VIEW PATENIEDmzmu's'.aa7.a52 v Fla 60 Ms W ECP EcP PRESSURE SHEET POD A A A A A A A'A A AA. BLUE SENS-AgX+ r AAAA'AAAAAA YELLOWCF NEGATIVE YELL0W FILTERRECORDING A -A A A A A A A A A A GREEN SENS. AgX+ AAAAAAAAAA MAGENTACF,905 GEL. sen LAYER N AAAAAAA-AAAA,V{REDSENS'AQX+ 'AAAAAAAAYAA CYANCFNDCF+ CARBON BLACK IMAGE --Ti0 LAYER RECEIVING --M T SIDE -"OXIDIZINGAGENT "-TRANSPARENT SUPPORT COLOR DIFFUSION TRANSFER PROCESS UTILIZINGAZO COUPLING TO ACTUATE DIFFUSION OF COLOR PROVIDING SPECIES BACKGROUNDOF THE INVENTION 1. Field of the Invention The invention relatesgenerally to a method of obtaining color reversal transfer images withnegative emulsion systems utilizing azo dye formation as thesolubilizing transport mechanism of the system.

2. Description of the Prior Art The broad use of azo dyes in amulti-color diffusion reversal transfer process is not by itself a novelmethod, see British Pat. No. 1 157505 to Ilford Limited and Renfrew U.S.Pat. No. 3,329,590, nor is the solubilization by reacting azo dyes withoxidized p-phenylene diamine in exposed imagewise areas a new method.Oxidative decoupling is taught in Barr, U.S. Pat. No. 3,227,551. In allof these cases of the prior art an azo dye is either the original colorformer or the end prod uct imaging dye as in British Pat. No. 804,976.In the present proposed system of the invention, the use of a diazoniumsalt, in the proper timing sequence, effects diffusion transfer from analready imaged or imaging silver halide layer, and the resulting azodyes are employed only as the means of transporting color formers. Theazo dyes are mordanted onto the receiving sheet until enough oxidizedp-phenylene diamine is formed to convert the azo dyes to azomethine orindo-aniline dyes.

SUMMARY OF THE INVENTION A positive multi-color diffusion product isconstructed by coating a negative film package of blue, green, and redsensitive emulsion layers containing 4- equivalent yellow, magenta andcyan oil soluble color formers, respectively and diazonium salts ordiazonium precursors which give mobility to the color formers.

In apreferred embodiment the diazonium salt or its precursor may beplaced behind a polymeric timing layer to thereby delay the diffusion ofthe color providing species until development has proceededsubstantially to completion. This permits an added measure of controlover earlier color former based color transfer processes (see U.S. Pat.Nos. 2,661,293 and 2,647,049).

In another form of the invention non-diffusing diazonium precursors areplaced between the emulsion layers to couple with the 4-equivalentcouplers which are themselves slightly soluble and diffusible at theoperating or development pH to generate highly diffusible species.

The diazonium salts or their precursors may also be placed within theemulsion layers forming the highly diffusible azo species upon alkalinetreatment (i.e., when subjected to the developer solution). This is animprovement over the alkali actuated diffusion process of the prior artinasmuch as preceding color formers were mobilized either by ionization(thus generating a much slower moving species) or by utilization ofcarboxylic or sulfo groups with like color formers (which endowed themwith a certain degree of diffusibility even at neutral pH and thus ahindrance during coating). (See U.S. Pat. Nos. 2,661,293, 2,647,049,2,661,293 and 3,359,104).

in U.S. Pat. No. 3,301,772 are not so 5 dowed.

In the operation of the invention, exposure is followed by treatmentwith an alkaline processing solution containing a N,N-dialkylsubstituted paraphenylene diamine which reduces the exposed silverhalide grains and couples with either the color formers or azo dyes,insolubilizing them, thereby leaving an imagewise distribution ofsoluble dye providing species. The flow of such species is facilitatedby a mordanting sink action in the positive or receiving portion of thefilm package where application of an oxidizing agent or the use ofincorporated oxidizing agent or other methods of generating oxidizeddeveloper (see U.S. Pat. No. 3,301,772) converts the azo dye to anindoaniline or azomethine dye thereby rendering the recorded origi nalscene faithful in regards to hue, color and density variations.

The advantages of using diazonium salt actuated diffusion are at onceobvious in view of the accelerated flow and sink action and thusconstitute an improvement to the existing art in photography.

By the use of diazonium salts or their precursors the line ofdistinction between mobile and immobile color providing species becomeseasy to regulate. As in prior art processes (see U.S. Pat. Nos.3,301,772 and 3,359,104), the use of alkali to generate diffusiblespecies requires ionization of the color formers involved which is animprecise and cumbersome method of solubilization. The former methodalso has the disadvantage of producing slowly diffusible species andlimits the selection of color formers to those which are essentiallyimmobile at the development pH but diffusible at a higher pH.Furthermore, the mechanism of raising the pH within a given period oftime is unavoidably complex. Last of all, neutralization of this alkaliin the final film package, to generate a stable dye image, requires morestringent methods than that necessary within the scope of the presentinvention, as anyone skilled in the art can plainly see.

The existence of an azo dye rather than a 4- equivalent color formeralso has the benefit of reducing the requirements of oxidizing agentsincorporated into the receiving sheet, for conversion, to one-half thatof prior art systems since the formed azo dyes act as 2- equivalentcouplers. (See Chapter 17, Mees, The Theory 0f the Photographic Process,Third Ed., 1966).

By using color formers in any of the three embodiments detailed above,the rate of diffusion is readily regulated by virtue of the placement ofcarboxy, sulfo or any number of these groups upon the diffusionactuating species. Thus, as in the case of the preferred embodiment themobilizing species may be made to be extremely diffusing and hence uponintroduction of the diazonium salt or its precursor at a given point(predetermined by the delay, provided by the timing layer) an almostinstantaneous coupling reaction ensues providing a mobilization of thecolor providing species which is so rapid that further modulation of theazo dye is almost impossible and hence misinformation referred to in theart as cross-talk is avoided.

DESCRIPTION OF THE PREFERRED EMBODIMENT The inclusion of the diazoniumcompound as a salt, a stabilized metal complex, or as a diazoniumprecursor such as an azo sulfone (all of which are well-known in theart) is an advancement of the art due to the greater mobility duringtransfer and the greater selection of 4- equivalent color formersavailable to the practitioner of this invention. A preferred embodimentsuggests the use of a delaying mechanism to effect transfer in order toprovide time for complete development of the negative image.

As a first preferred embodiment use is made of a diazonium salt orpreferably an azosulfone which is both soluble and diffusible at theprocessing pH either encapsulated or incorporated behind a timing layer.This timing layer may be any of a number of alkali degradable or solubleor permeable polymers which will permit a time lag between initiation ofdevelopment and diffusion of the diazonium species through the negative.As an example but in no way a limitation to this patent is the halfbutyl ester of maleic anhydride methyl vinyl ether copolymer which whencoated to a thickness of 1.5;1. offers a delay of about 50 seconds at pHll.5 before becoming permeable to the incorporated diazonium species.

Upon introduction of a buffered alkaline processing solution containinga N,N-dialkyl paraphenylene diamine (such as 4-N,N-diethylamino-Z-methylaniline) with the appropriate development accelerators (such as metoland phenidone), and a film forming thickening agent (such as carboxymethyl cellulose) the exposed light sensitive portion of the packageundergoes negative development resulting in an imagewise distribution ofnon-diffusible and unreactive azomethine or indoaniline dyes(corresponding to light struck areas) and 4-equivalent color formers(corresponding to un exposed portions of the film). After a given periodof time (between 30-60 seconds) full development has been effected andthe diazonium species are released from behind their timing layer toflow through the negative portion of the package, reacting with theleft-over couplers, to form an imagewise distribution of diffusible2-equivalent couplers as azo dyes. These species are then pulled in asink fashion to the receiving portions of the film where they aremordanted and converted to azomethine or indoaniline dyes by virtue ofoxidative coupling with oxidized N,N-dialkylparaphenylene diamine(either initially incorporated within the receiving layers or as part ofthat which was furnished from the processing solution) and oxidizingagent (either provided in the receiving layers as an incorporatedspecies or supplied by virtue of a post-transfer processing step, orcreated electrolytically) (see for example U.S.'Pat. No. 3,301,772).

The color formers utilized within this embodiment are preferably oilsoluble and essentially non-diffusible at the development pI-I but mustbe capable of diffusion after azo coupling. As examples of those colorformers which may be employed within the scope of the first embodimentare those listed in US. Pat. No. 3,369,104 which when the processingsolution is kept at pH l 1.5 or below are essentially immobile. Asexamples but again in no way a limitation to the scope of this patentare the diazonium salt and the diazonium sulfone 3- carboxy-4(l-pyrrolidinyl )benzenediazonium fluoborate and 5-phenylsulfonylazo-2( l-pyrrolidinyl) benzoic acidv As a second preferred embodiment is theutilization of non-diffusing azo-sulfones which are incorporated in thenegative between the emulsion layers. These species have the generalformula of SOL-DlAZ-LINK- MORD where SOL refers to any number ofsolubilizing groups, DIAZ is the diazonium portion of the molecule. LINKis a fragmentable function which binds the SOL- DIAZ to the mordantingportion of the molecule (MORD) but which cleaves from the DIAZ portionupon reaction with the 4-equivalent color formers. and MORD is anynumber of polymeric or long chain alkyl substituents which renders thediazonium precursor non-diffusible. As an example, but in no waylimitative to this patent, is N-(p-(-dodecyloxyphenylsulfonylazo)phenyl)-succinamic acid as a usefuldiazosulfone to be employed within this preferred embodiment.

As examples of color formers to be employed are those listed in US. Pat.No. 3,369,104 which. when the processing pH is rendered high enough (pH11.5 l3.0) achieve some degree of diffusibility, permitting them totransfer to an adjacent layer, due to the sink action of the reactionproviding azo-sulfone.

Upon introduction of a buffered alkaline solution containing aparaphenylene diamine developer. development accelerators and a filmforming thickening agent, all of which are similar to those of the firstpreferred embodiment, imagewise formation of dye is pro duced byimagewise formation of oxidized developer. Concurrent with this reactionis the diffusion of unreacted couplers to the adjacent azo-sulfonebearing layers where azo formation and a higher order of mobility isimparted to the color providing species. The following steps, after azoformation occurs, are the same as those of the first preferredembodiment.

As examples of diazonium salts or azosulfones which may be employedwithin the scope of the invention, mention may be made of the following:

K I I NiBi-u 3-carboxy-4-morpholinobenzenediazonium fluoborate3-carboxy-4( l-pyrrolidinyl)benzenediazonium t'luoborate3-carboxy-4-piperidinobenzenediazonium fluoborate 4.4(3-carboxypropionamido)benzenediazonium hexafluoarsenate NII -C ocmcmc0011 4( l-pyrrolidinyl)3-sulfobenzenediazonium inner salt 7) rs Ezonzomsoy 4-[ethyl( 2-sulfoethyl )amino]o-toluene-diazonium inner salt5-phenylsulfonylazo-2( l-pyrrolidinyl)benzoic acid TH-COOH OH C O OHN-[p-(p-Dodecyloxyphenylsulfonylazo)phenyl]succinamide acid BRIEFDESCRIPTION OF THE DRAWINGS FIGS. 1, 4, and 5 are diagrammatic enlargedcrosssectional views of three non-peel apart film units embodying theinvention.

FIG. 2 is a diagrammatic cross-section of FIG. 1 after exposure hastaken place and the film unit has been subjected to roller application.

FIGS. 3, a, b, c, d are descriptive formula of the reactions of negativedevelopment, azo dye formation employing azo-sulfones, indoaniline dyeformation and azo dye formation employing a diazonium salt.

FIG. 6a is a diagrammatic enlarged cross-section of a film unitemphasizing the use of timing layers and receiving sheet.

FIG. 6b is a diagrammatic enlarged cross-section of a non-peel aparttwo-piece package employing a pressure sheet containing diffusiblediazonium species behind a timing layer.

DETAILED DESCRIPTION OF THE INVENTION Oxidative coupling betweenN,N-dialkylparapheny- Iene diamines and color formers, whether4-equivalent or as their Z-equivalent azo derivatives, is well known andamply described in The Theory of the Photographic Process, Chapter 17,Third Ed. (1966) by Mees. Reactions between diazonium salts or azosulfones and various couplers are also well documented as described inThe Chemistry of the Carbon-Nitrogen Double Bond, Chapter 2, Ed. by SaulPatai (1970), and US. Pat. No. 3,661,573. The employment of the formeras a method of image formation along with the latter as a means ofdiffusion actuation is unique, however.

The combination of both of these mechanisms permits the use ofcolorless, color providing species within the emulsion layers, and hencea diversity not readily afforded to most other color transfer processesis available, whereby a multitude of layer arrangements and packageconfiguration is possible.

The following examples serve as illustrations as to the possibleemployments of our invention and to facilitate the teaching of theconcepts described therein. They should not be accepted as the onlyarrangement possible by which the invention may be employed asvariations of package construction are obvious to those skilled in theart. Neither should the suggested employment of specific opacifyingagents, reflective agents or the like be construed to limit the scope ofthe invention as equivalent substitutions are readily obvious to thoseskilled in the art and are omitted for the sake of brevity and a clearerdescription of the teachings of the inventron.

FIGS. 1 and 2 exemplify one preferred means by which the invention maybe practiced. The layers of FIGS. 1 and 2 embody the conceptualemployment of non-diffusing diazonium precursors placed in the gelatinseparation layers between the light sensitive layers. The diagrammaticcross-section of FIG. 2 describes the film package as shown in FIG. Iafter it has been subjected to roller application and the processingsolution described in layer 9 has been extruded between layers 8 and 10.As shown in FIG. 1, exposure and final viewing of the finished printoccurs from the same side. The package therefore is most aptly employedin an imaging system referred to as Lateral Reversal corrected, see E.H. Land, Photogr. Sci. Eng., 16, 247 (I972).

Layer 1 of FIG. 1 is an opaque diazosulfone pigmented film base such aspolyester, polycarbonate, cellulose acetate, cellulose acetate butyrateand the like with a thickness of 2 /2 to 9 mils. It serves the dualfunction of a support as well as a barrier to unwanted exposure byvirtue of an opacifying agent such as carbon black, titanium dioxide,combinations of same or the like which is constructed as part of thebase or coated upon the base. Layer 2 is a gelatin matrix layercontaining a non-diffusing diazonium precursor such as a diazonesulfonewhich is capable of reacting with 4- 'equivalent color formers underalkaline conditions forming alkali soluble and highly diffusible azodyes.

Layer 3 is a red-light-sensitive silver halide emulsion layer containingan oil dispersion of cyan 4-equivalent color former which becomes onlymoderately diffusible under the influence of the alkaline processingsolution, but which forms a highly mobile azo dye with the diffusionactuating diazonium precursor.

Layer 4 is a gelatin separation layer of the same composition as layer2.

Layer 5 is a green-light sensitive silver halide emulsion layercontaining an oil dispersion of magenta 4- equivalent color former whichbehaves as the cyan component in layer 3.

Layer 6 is a gelatin matrix layer containing a nondiffusing diazoniumprecursor such as a diazosulfone as in layers 2 and 4 and a blue lightabsorbing species such as yellow colloidal silver which prevents bluelight from reaching layers 3 and 5.

Layer 7 is a bIue-light-sensitive silver halide emulsion layercontaining an oil dispersion of 4equivalent yellow color former whichbehaves as the cyan and magenta color formers of layers 3 and 5.

Layer 8 is a gelatin matrix layer containing a nondiffusing 4-equivalentcolor former or any such species which willreact with any amount ofdiazonium salt that might be produced after processing has beencompleted. The product thus produced will not be diffusible and hence noimage degradation will occur.

Layer 9 is a pressure rupturable processing pod containing a p-phenylenediamine developer, an antioxidant, alkali, a film forming thickeningagent, and opacifying agent such as TiO or the like along with auxiliarylight blocking or absorbing agent such as carbon black, non-diffusibledyes, or the like in sufficient concentration as to assure fulldevelopment of all silver halide in fully exposed regions and to protectthe negative portion of the film from further exposure when removed fromthe camera.

Layer 10 is a gelatin matrix layer containing a reflective species orits precursor which by virtue of its coated form or its concentration orthe layer thickness is relatively transparent to actinic radiation butsubsequent to application of the processing solution becomes opaqueenough to act as a visual barrier to the auxiliary opacifying agent ofthe pod. As an example. but in no way a limitation, is titanium dioxidecoated at a 10 percent concentration in 6 percent gel solution wherebythe particle size prior to processing is of a mean average size lessthan 005p, but after processing a mean average size due to coagulationof 05p. or greater.

Layer I1 is a mordanting receiving layer of acid treated gelatin andacid mordanting polymeric or nondiffusing basic substances such as aminoguanidine derivatives.

Layer 12 is a polymeric timing layer such as polyvinyl alcohol or thelike as listed in U.S. Pat. No. 3,455,686 and containing encapsulatedoxidizing agents, such as potassium persulfate.

Layer 13 is a pH lowering layer composed of or containing polymericacids or anhydrides as listed in US. Pat. No. 3,362,819.

Layer I4 is a transparent film base such as polyester, polycarbonate,cellulose acetate, cellulose acetate butyrate and the like with athickness of 2% to 9 mils.

Layer 15 is a pressure sensitive tape as a binder to hold the negativeelement permanently bound to the image receiving element and theprocessing pod.

Subsequent to exposure the package as shown in FIG. 1 is either manuallyor mechanically forced between rollers which extrude the contents of thepod thereby forming layer 9 as shown in FIG. 2. Upon introduction of theprocessing solution, development proceeds as chemically visualized forthe cyan layer in FIG. 3a. In unexposed regions, the color formers oflay ers 3, 5, 7 which are themselves soluble and slightly diffusible atthe processing pI-I, are pulled in a sink fashion to the diazosulfonebearing layers of 2, 4 and 6 in which the reactions of azo formationdepicted in FIG. 321 for layer 2 proceeds. The azo dyes thus generatedmigrate to the receiving portion of the package (layer 11) where theyare mordanted and then converted to the appropriate indoaniline orazomethine dyes by virtue of oxidative cleavage and coupling withoxidized paraphenylene diamine as shown in FIG. 30.

FIGS. 4 and 5 are further illustrative examples of layer arrangements tobe employed in the practice of the invention. Unlike in FIGS. 1 and 2,exposure and viewing take place at opposite portions of the film packageand hence laterally reversed cameras which are the design most oftenutilized in the photographic field, may be employed in conjunction withthese layer arrangements. It is important to note that only withcolorless color providing material may both such constructions exist,and hence employment of the invention and the configurations describedabove and below offers an advancement of the art to the practice ofinstant access color photography with regards to the selection of imagerecording devices to be employed.

FIG. 4 empioys a single pod construction of a nonpeel-apart package,while FIG. 5 employs a double pod construction. The layers of FIGS. 4and 5 may be defined as:

Layers 2 through 15 are described as above for FIGS.

1 and 2;

Layer 16 is a gelatin matrix layer containing a nondiffusing4-equivalent coupler as described in layer 8 plus opacifying agents suchas non-diffusing dyes or carbon black or the like to render that portionof the package opaque to unwanted exposure:

Layer 17 is a white opaque pigment light reflective layer of TiO andgelatin;

Layer 18 is as described in layer 14;

Layer 19 is a pressure rupturable pod containing a thickening agent andcarbon black in a form of a paste as described in US. Pat. No.3,635,707;

Layer 20 is a support layer as described in layer 14.

Just as the employment of colorless color providing 4-equivalentcouplers and non-diffusing diazonium precursors offer a superior degreeof diversity as to the layer arrangements which may be utilized, theemployment of 4-equivalent color formers and diffusible diazonium saltsor precursors when employed with a timing layer also permit the use ofeither the laterally reversed or laterally reversed corrected opticalsystems.

FIGS. 6a and 6b employ the laterally reversed corrected and laterallyreversed systems respectively. In the employment of the invention asshown in FIGS. 6a and 6b, the negative portion of the film and thepressure sheet or receiving sheet may initially be separate or may bejoined as in FIGS. 1, 2, 4 and 5. The mechanism of image recording andnegative development are essentially alike that described above, but thetransport mechanism is sufficiently unique to warrant its owndescription.

After imaging and introduction of the processing solution developmentproceeds as described'in FIG. 3a, leaving an imagewise distribution ofimmobile azomethine and indoaniline dyes and unreacted 4-equivalentcolor formers (corresponding to unexposed portions of the film package).After development has proceeded substantially to completion a timinglayer which contains the diazonium salt or diazonium precursor breaksdown or solubilizes thus releasing the entrapped species. The mobilediffusion actuating diazonium now migrates throughout the film packagecoupling with the remaining 4-equivalent color formers to produce animagewise diffusion of azo dyes (see FIG. 3d). The azo dyes are in turntransferred to the receiving portions of the package where oxidizeddeveloper, generated by incorporated oxidizing agent converts them intoazomethine or indoaniline dyes. To facilitate understanding of thepreferred embodiments in the examples, only diazonium salts (2) and (5)are illustrated below, but all salts disclosed can be used, and itshould be understood that these salts are only a few of many salts or ofaromatic azo sulfones or of diazonium precursors which provide the newand superior results of the invention.

EXAMPLE I To 50 ml of a bromoiodide emulsion containing 5 percent ofsilver was added 0.6 g of diazonium salt 2 and 3 ml of a color formerdispersion containing 8 percent color former as shown in FIG. 3a in 12percent of dispersing oils dibutylphthalate and tricresylphosphate. Theresulting formulation was coated with the aid of surfactants such asSaponin or Tergitol No. 4, on a clear film base of cellulose acetatebutyrate. The dried coating. containing about I g of silver/m wasexposed imagewise and brought into contact with an opaque receivingsheet containing l-(4-decoxyphenyl)-biguanide in gelatin as a mordantwith a concurrent application of a processing solution of the followingformulation:

CD-2 is a color developer which is 4-N,N diethyl amino 2 methyl anilinemonohydrochloride or salt as supplied by Eastman Kodak Co.

Tergitol is defined in Hackhs Chemical Dictionary, 3rd Edition, at page836 as a polyethylene oxide surfactant.

Alipal CO-436 is ammonium salt of sulfated nonyl phenoxy poly(ethyleneoxy) ethanol.

After 20 seconds of contact, the receiving sheet was peeled from thenegative. At this point, the negative material exhibited a cyan image onan orange-yellow background and the mordant-receiving sheet exhibited apositive orange-yellow image. Treating the receiving sheet with 5percent potassium ferricyanide solution, followed by washing, resultedin a positive cyan image.

EXAMPLE 2 A negative layer similar to that of Example 1 but without theincorporation of the diazonium salt was coated and processed as inExample 1. After five minutes, the negative and receiving sheet wereseparated. The receiving sheet was treated with 5 percent potassiumferricyanide but no color was generated, thus indicating that alldiffusion of color providing species in Example 1 was induced by azoformation.

EXAMPLE 3 A mordant bearing receiving sheet was prepared by coating asubbed white opaque film base such as baryta coated paper, with agelatin solution of l-(4 -decoxyphenyl)biguanide. The coatingformulation was prepared by adding to 500 ml of a 3 percent gelatinsolution, 3.0 g of l-(4-decoxyphenyl)biguanide and 1.5 ml of glacialacetic acid. The mixture was held at 50C until solution was complete(about 15 minutes) and then cooled to 40C with 2.5 ml of a 6 percentacetone solution of l,4-butanediol diglycidyl ether added as a hardener.The resulting gelatin solution was then dip coated at 40C to a thicknesswhich would generate a concentration equivalent to that of the azo dyeto be mordanted.

EXAMPLE 4 On a clear cellulose acetate butyrate film base was coated, asa mordant, an acid treated gelatin solution to a thickness of 10a. Overthis receiving layer was then coated a 4 percent lime treated gelatinsolution exhibiting an isoelectric point at pH 5 containing titaniumdioxide at a concentration of 10 percent. The thickness of this secondlayer was 8.7;], and it thus gave transmission readings of 1.0 for blue,green, and red light and reflection readings of 0.1 or less.

EXAMPLE 5 A layer of gelatin bearing diazonium salt was pre pared bydissolving 2.0 g of diazonium salt in 100 ml of 6 percent gelatinsolution and adding 10 ml of 10 percent acetic acid, 5 ml of 8 percentSaponin and 2 ml of 5 percent triacrylformal. The solution was thencoated to 10p. thickness on clear cellulose acetate butyrate film base.

EXAMPLE 6 EXAMPLE 7 To 1.0 ltr. of 2 percent ECP solution prepared inExample 6 was added 2.2 ltr. of water and 0.4 ltr. of polyurethane latex(40 percent). This solution was then coated at 5 and 10p thicknessesover the diazonium coating of Example 5. A table of time versus timinglayer thickness for various pH ranges is recorded below. The testingscheme utilized a water soluble diazo- -nium coupler at a concentrationof 0.1 g per 100 ml of alkaline solution. Potassium hydroxide at variousconcentrations was employed to adjust the pH levels.

Thickness Time (Sec) of H DH pH pH pH pH ECP 13.3 13.0 12.8 12.5 12.211.8

0 1 3 4 4 7 16 Spt 5 7 14 14 33 90 10p. 7 10 14 22 67 180 EXAMPLE 8National Starch Resin 1310 (1:4 crotonic acid, vinyl acetate co-polymer)was found to be a viable timing species when solvent coated at aconcentration of 10g solid in a 200 ml ethanol/methanol mixture (1:1).To determine its delaying action the resin was coated over 'a colorpaper stock and processed in the developer formulation of Example 1 inwhite light. Using untreated stock as a standard the National Starchresin was found to give a 15 second delay at 5p. thickness and a 30second delay at 10p thickness at a pH of 10.7.

EXAMPLE 9 Gantrez ES 425 (the half butyl ester of maleic anhydridemethyl vinyl ether copolymer) made by GAF Corporation, was found to givea delay to the penetration of alkali. The Gantrez was dip coated to alayer thickness of 1.5 p. onto white lighted panchromatic film from a 4percent solution in absolute alcohol. A 1 percent hydroquinone solutionat pH 1 1.5 with sodium hydroxide as the alkali indicated a timing delayof 0.8 minutes at 75F.

EXAMPLE 10 Over the receiving layers as described in Example 4 wascoated a cyan dispersion (no silver) as described in Example 2. Thispackage was then soaked in an ammonium hydroxide solution, pH 12.3, forone minute and placed in contact with a portion of the diazonium coatingmentioned in Example 5 and imaged with UV radiation. After a contact of30 seconds an azo dye image was observed in the positive portion of thepackage (behind the TiO layer). The pressure sheet was peeled off andthe positive was soaked in the developer formulation of Example 1 andconverted to the cyan indoaniline dye by soaking for 15 seconds in 2percent ammonium persulfate solution.

EXAMPLE 1 l A sample of the diazonium releasing package described inExample 7 with a thickness of ECP of 51.1. was overcoated with thenegative formulation of Example 2 to a thickness of 30 The negative wasimaged through a photographic stepwedge and then placed in contact witha receiving sheet of a construction and formulation of Example 3 whichhad a thickness of 5p. with a simultaneous application of the processingsolution mentioned in Example 1 but adjusted to pH 12.0 with KOH. Aftera contact time of 45 seconds, an orange positive image (azo dye) on ayellow background (diazonium salt) was observed. Treating the receivingsheet with 2 percent ammonium persulfate discharged the yellow diazoniumand converted the orange azo dye to the cyan indoaniline dye.

EXAMPLE 12 A negative package is coated as in Example 1 l but with oneaddition. Over the cyan containing emulsion is coated. to a thickness of5a, a dispersion of oil soluble long chain 4equivalent coupler or asolution of long chain hydrophilic coupler in gelatin. The film packageis exposed and processed as in Example 11. After a contact time of 45seconds, an orange positive image on a white background is observed. Theyellow diazonium salt corresponding to developed areas does not proceedto the receiving sheet due to coupling in this barrier layer of4-equivalent coupler. Generation of the cyan image is as in Example 1 1.

EXAMPLE l3 SYNTHESIS OF NOVEL DIAZONIUM SALTS a.3-Carboxy-4-morpholinobenzenediazonium fluoborate NzBl 20.1 grams2-chloro-5-nitrobenzoic acid was added in portions to 87 ml morpholine.The temperature of the thick mixture rose to C after being stirred atreflux temperature for 5 hours, the mixture was poured into ice water.made acidic with cone. HCl, filtered. dried and recrystallized fromethanol to give 20.3 g 2-morpholino5-nitrobenzoic acid, melting point168 170C. This nitro compound was reduced catalytically to give5-amino-2-morpholinobenzoic acid, melting point 3078C. The amine wasthen diazotized in ethanol to give 3-c arboxy-4-morpholinobenzenediazonium fluoborate, dec. 146C.

b. 3-Carboxy-4(1-pyrrolidinyl)benzenediazonium fluoborate I -GOOll2-Chlor0-5-nitrobenzoic acid was reacted with pyrrolidine and gave5-nitro-2-( l-pyrrolidinyl)benzoic acid, melting point 2246C. The nitrowas reduced to give the amine, melting point 2058C, which was diazotizedin dilute HCl and gave 3-carboxy-4-( lpyrrolidinyl)benzenediazoniurnfluoborate, dec. 157-8C.

c. 3-Carboxy-4-piperidinobenzenediazonium fluobo- COOH5-Nitro-2-piperidinobenzoic acid, prepared according to Journal ChemicalSociety 1117 (1927), was reduced catalytically and the amine, meltingpoint 232-5C, was diazotized in ethanol to give the diazo, dec. l40lC.d. 4(3-carboxypropionamido)benzenediazoniumhexafluoroarsenate bllHCOCHnCHq C 0 OH Sodium2[methyl(2-sulfoethyl)aminol-S-nitrobenzene-sulfonate was preparedfollowing a method described in Part 11 of Bios Report No. 986 andreduced catalytically in ethanol-water (2:1) to give the amine which wasdiazotized in dil. HCl. giving the desired sodium4-[-methyl(2-sulfoethyl)amino]-3- sulfobenzenediazonium inner salt. Dec.239-24lC.

f. 4( l-pyrrolidinyl)3-sulfobenzenediazonium inner salt2-Pyrrolidinyl-5-nitrobenzenesulfonic acid was prepared by adding 72.4 gof 2-chloro-5-nitrobenzenesulfonic acid in portions to 134 mlpyrrolidine keeping the temperature below 65C. After the addition thereaction was allowed to stir at reflux temperature for 7 hours andpoured into 800 ml ice water. The solution was made strongly acidic withconc. I-lCl until precipitation of yellow crystals was complete.Filtered and washed with a little dil. HCl, the moist cake wasrecrystallized from water to give 70.7 g of the nitro compound dec.178-9C.

The above nitro was reduced catalytically to give the amine, dec.255-56C. 24.2 g of the amine was diazotized in dil. HCl and isolated bypouring the diazo solution into ethanol. After cooling the diazo wasfiltered, washed with ethanol and vacuum dried to give 19.3 g of diazo,sudden dec. at 157C.

V I l2 4-Amino-N-ethyl-3-methyl-N-(B-sulfoethyl)aniline was preparedaccording to the procedure described in Journal American ChemicalSociety, 78, 5827. This amine (14.0 g) was diazotized in ethanol withn-butyl nitrite to give the desired diazo (12.0 g) 4-[Ethyl(2-sulfoethyl)amino]o-toluene-diazonium inner salt.

Darkens and dec. 200C. h. 5-Phenylsulfonylazo-2( l-pyrrolidinyl)benzoicacid COOH 5-Nitro-2-pyrrolidinylbenzoic acid (15 g) was dissolved in mlwater, 37 ml formic acid and 11 ml conc. HCl. This solution wasdiazotized at 5l0C with 1 1.6 ml sodium nitrite (5M). After one-halfhour the excess nitrite was destroyed with sulfamic acid and 13.1 gsodium benzenesulfinate dissolved in 30 ml water was added. The mixturewas allowed to stir for 1 hour and the gummy precipitate started tocrystallize on standing overnight under refrigeration. The solid wasfiltered and triturated with methanol, filtered, vacuum dried to give11.4 g of diazo sulfone dec. 127-130C.

i) ITTHCOCHzCI-IaCOOH 4-Docecyloxybenzenesulfonyl chloride (10 g),prepared according to Journal Chemical Society (1946) 865, ml ether, 1ml water was treated with 5 g zinc dust and allowed to stir at roomtemperature for onehalf hour. Added an additional 50 ml ether and themixture was stirred at reflux temperature for 3 hours. The mixture wasfiltered and the filter cake was treated with a solution of 5 g sodiumcarbonate dissolved in 250 ml. water. The mixture was heated to the boiland the insolubles were hot filtered off. The filtrate cooled to give5.9 g of sodium 4-dodecyloxybenzenesulfinate.

2 g of the above sulfmate was dissolved in a mixture of 80 ml of water,80 ml ethanol, 80 m] methanol. To this filtered solution was added asolution of 2 g 4(3- carboxypropionamido)-benzenediazoniumhexafluoroarsenate in ml water and 5 ml ethanol. The yellow precipitatewas stirred at room temperature for 15 minutes. The precipitate wasfiltered, washed with water and dried in a vacuum to give 2.8 g ofN-{p-(p- Dodecyloxyphenyl-sulfonylazo)phenyl]succinamic acid dec.Ill-113C.

We claim:

1. A photographic film package for producing a positive color image,comprising:

a. at least one light sensitive silver halide emulsion layer, eachemulsion layer being sensitized to the spectrum of a different primarycolor;

b. each said emulsion layer containing a 4-equivalent color former whichyields a complementary color to the primary color of said emulsionlaYer, said color former being incorporated in a high boilingphotographically inert oil droplet dispersion uniformly distributedwithin said emulsion layer; said color former having substantially nowater solubility and substantially no mobility at pH below about 9 andbeing capable of reacting with oxidized color developer to form animmobilized coupled product at exposed areas;

c. a benzene diazonium salt, or precursor thereof,

containing at least one group independently selected from carboxy andsulfo and being capable of azo coupling with said color former to form ahighly diffusible azo dye;

d. one of said color former and said diazonium salt or 60 precursorthereof being non-diffusible at the development pH and the other beingat least slightly diffusible at the development pH to allow said azocoupling to proceed, after imagewise exposure and color development ofsaid package with an alkaline 6 processing solution containing a colordeveloper, between color former that has not reacted with oxidized colordeveloper and said diazonium compound or precursor thereof to form saidazo dye; and

e. a receiving portion having chemical means for mordanting azo dye thathas diffused thereto and converting mordanted azo dye into immobilizedazomethine or indoaniline dyes,

2. The package according to claim 1. wherein the color former isnon-diffusing at the development pH and the benzene diazonium salt orprecursor thereof is highly diffusible at the development pH. thebenzene diazonium salt or precursor thereof being separated from saidcolor former by a timing layer that releases said diazonium salt orprecursor thereof for diffusion after color development is substantiallycompleted.

3. The package according to claim 1, wherein c) is a benzene diazoniumsalt or precursor thereof which is non-diffusing at the development pHand which is incorporated in a separation layer adjacent each saidemulsion layer, and said color former is slightly diffusible at thedevelopment pH to at least an extent to enable diffusion of the colorformer from its emulsion layer to the benzene diazoniumprecursor-containing layer adjacent thereto.

4. The package according to claim 1, wherein said color former and saidbenzene diazonium salt or precursor thereof are both in the emulsionlayer.

5. The package according to claim 1, wherein the benzene diazoniumprecursor is a benzene azo sulfone 6. The package according to claim 2,wherein the color former is essentially non-diffusible at pH less than11.5 and the benzene diazonium salt or precursor thereof is 3-carboxy-4(l -pyrrolidinyl)benzenediazonium fluoborate,5-phenylsulfonylazo-2(lpyrrolidinyl) benzoic acid, or4-[methyl-(2-sulfoethyl)- amino1-3-sulfobenzenediazonium inner salt.

7. The package according to claim 3, wherein the non-diffusing benzenediazonium precursor is N-[p- (dodecyloxy-phenylsulfonylazol-phenyl1succinamic acid.

8. The package according to claim 4, wherein the benzene diazonium saltis 3-carboxy-4( l-pyrrolidinyl)- benzene-diazonium fluoborate.

9. The package according to claim 1 wherein the polymeric timing layeris the half butyl ester of maleic anhydride methyl vinyl ethercopolymer.

10. The package according to claim 1 wherein the polymeric timing layeris 1:4 crotonic acid, vinyl acetate copolymer.

11. The package according to claim 1 wherein the polymeric timing layeris a mixture of ethyl cellulose phthalate and polyurethane latex.

12. A photographic film package for producing a positive color image,comprising:

a. at least one light sensitive silver halide emulsion layer, eachemulsion layer being sensitized to the spectrum of a different primarycolor;

b. each said emulsion layer containing a i-equivalent color former whichyields a complementary color to the primary color of said emulsionlayer, said color former being incorporated in a high boilingphotographically inert oil droplet dispersion uniformly distributedwithin said emulsion layer; said color former having substantially nowater solubility and substantially no mobility at pH below about 9 andbeing capable of reacting with oxidized color developer to form animmobilized coupled product solution containing a color developer; andat exposed areas; (1. a receiving portion having chemical means for c.said emulsion layer also containing a benzene dia mordanting azo dyethat has diffused thereto and zonium salt, or precursor thereof,containing at converting mordanted azo dye into immobilized least onegroup independently selected from carazomethine or indoaniline dyes.boxy and sulfo and being capable of azo coupling 13. The packageaccording to claim 12, wherein the with said color former to form ahighly diffusible benzene diazonium salt is 3-carboxy-4(1-pyrrolidinyl)-azo dye after imagewise exposure and color devel benzenediazoniumfluoborate. opment of said package with an alkaline processing

2. The paCkage according to claim 1, wherein the color former isnon-diffusing at the development pH and the benzene diazonium salt orprecursor thereof is highly diffusible at the development pH, thebenzene diazonium salt or precursor thereof being separated from saidcolor former by a timing layer that releases said diazonium salt orprecursor thereof for diffusion after color development is substantiallycompleted.
 3. The package according to claim 1, wherein c) is a benzenediazonium salt or precursor thereof which is non-diffusing at thedevelopment pH and which is incorporated in a separation layer adjacenteach said emulsion layer, and said color former is slightly diffusibleat the development pH to at least an extent to enable diffusion of thecolor former from its emulsion layer to the benzene diazoniumprecursor-containing layer adjacent thereto.
 4. The package according toclaim 1, wherein said color former and said benzene diazonium salt orprecursor thereof are both in the emulsion layer.
 5. The packageaccording to claim 1, wherein the benzene diazonium precursor is abenzene azo sulfone.
 6. The package according to claim 2, wherein thecolor former is essentially non-diffusible at pH less than 11.5 and thebenzene diazonium salt or precursor thereof is3-carboxy-4(1-pyrrolidinyl)benzenediazonium fluoborate,5-phenylsulfonylazo-2(1-pyrrolidinyl) benzoic acid, or4-(methyl-(2-sulfoethyl)-amino)-3-sulfobenzenediazonium inner salt. 7.The package according to claim 3, wherein the non-diffusing benzenediazonium precursor is N-(p-(dodecyloxy-phenylsulfonylazo)-phenyl)succinamic acid.
 8. The package according to claim 4, wherein thebenzene diazonium salt is 3-carboxy-4(1-pyrrolidinyl)benzene-diazoniumfluoborate.
 9. The package according to claim 1 wherein the polymerictiming layer is the half butyl ester of maleic anhydride methyl vinylether copolymer.
 10. The package according to claim 1 wherein thepolymeric timing layer is 1:4 crotonic acid, vinyl acetate copolymer.11. The package according to claim 1 wherein the polymeric timing layeris a mixture of ethyl cellulose phthalate and polyurethane latex.
 12. Aphotographic film package for producing a positive color image,comprising: a. at least one light sensitive silver halide emulsionlayer, each emulsion layer being sensitized to the spectrum of adifferent primary color; b. each said emulsion layer containing a4-equivalent color former which yields a complementary color to theprimary color of said emulsion layer, said color former beingincorporated in a high boiling photographically inert oil dropletdispersion uniformly distributed within said emulsion layer; said colorformer having substantially no water solubility and substantially nomobility at pH below about 9 and being capable of reacting with oxidizedcolor developer to form an immobilized coupled product at exposed areas;c. said emulsion layer also containing a benzene diazonium salt, orprecursor thereof, containing at least one group independently selectedfrom carboxy and sulfo and being capable of azo coupling with said colorformer to form a highly diffusible azo dye after imagewise exposure andcolor development of said package with an alkaline processing solutioncontaining a color developer; and d. a receiving portion having chemicalmeans for mordanting azo dye that has diffused thereto and convertingmordanted azo dye into immobilized azomethine or indoaniline dyes. 13.The package according to claim 12, wherein the benzene diazonium salt is3-carboxy-4(1-pyrrolidinyl)benzenediazonium fluoborate.